Telephonic receiver



April 26,1927. 1,625,995

E. A. GRAHAM I TELEPHONIC RECEIVER Filed May 51, 1924 2 Sheets-Sheet l April 26,1927.

E. A. GRAHAM TELEPHONIC RECEIVER Filed May 31. 1924 Sheets-Sheet 2 Patented Apr. 26, 1927.

' .um rsu STATES EDWARD ALFRED GRAHAM, or 'nRoc'xLaY,

GRAHAM EXECUTBII AND EXECUTOR 3 l).

ENGLAND, MARIA enAnAm Am) Anrnnn or-sArn EDWARD Anrasn GRAHAM, na-

TELFPHONIQ RECEIVER.

Application filed Kay 81, 19524, serial No. 717,063, and in Great Britain June 14, 1823.

- In telephone receivers in which a diaphragm is caused to vibrate for the purpose of sound emission or origination ofsoun waves by electro-magnetic means, itiscus- 5 tomary firmly to clamp the diaphragm at .its peripheral edge portion between, two metal plates or flanges, with or without the interposition of washers; of hard rubber, fibre, or other material of similar character, in order to ensure, as far. as possible, an equable and comparatively rigid clamp with a view to preventing chatter when close adjustment is made of the electro-mag'netic system relative to the diaphragm, or, in

i some instances, to an armature to which the diaphragm is attached. 7

In a eneral way itis of course known that a iaphragm may be retained, held, suspended or maintained in position in such a manner as to avoid the setting up therein of an initial strain or stress which otherwise imparts a certain frequency of vibration to the diaphragm when the latter is in use, or accentuates the inherent natural frequency of the diaphragm It would not, however, be sufiicient in the case of. diapgragms of telephonic receivers of the type own as loud speakers, to which the present invention particularly relates, to, provide for this -w1thout ensuring that the initial adjustment of the diaphragm shall remain stable, and the object ofthe present .invention is to maintain the requisite stability.

To this end, the invention consists in arranging that the diaphragm shall be marginally supported at the side next to the electro-magnetic influencing system in a definitely limited manner whilst acted uponat' the opposite side by means of a comparatively yielding or elastic character. In this way the diaphragm is electro magnetically attracted towards and against a substantially rigid bed or seating, but is only elastically held, supported or retained at the opposite side by means against which the diaphragm could be mechanically dlsplaced with relative ease.

The carryin out of the invention may be efl'ected in various ways by employment of gaskets, resilient spring and like devices I which in themselves are broadly known and form no partof the present invention, other- 1 wise than in their arrangement and combination for the purpose set forth, as will be.

In the accompanying drawings, Figs. 1 to 5 inclusive illustrate various ways of carrying the invention into practice. Figs. 1" and 1 show respectively in side view and plan part of abearin ring with a s ring finger thereon used in t earran ements own inFig. 1'. Fig. 2 shows in si e view, part of a bearing ring with spring fingers used in the arrangement shown in 2. Fig. 4 shows part of a bearing ring with spring fingers-used in the arrangement shown in Fig. 4. Figs. 5f and 5 show part of a ring with alternative forms of spring fingers for use in the arrangement shown in Fig. 5.

According to the construction shown in Figs. 1, 1, 1 the casing a of the telephonic receiver is provided at its front end with an external flange b and formed with an internal recess a in which is inserted a diaphragm d, embraced on opposite sides of its peripheral portion by a solid ring of rubber, felt, cloth or like sound deadening or damping material (hereinafter referred to fordistinction, as the rubber ring) which is of the channel shape in cross section. To the flanged end of the casing is secured, it may be by screws, an end plate or cover f having a central sound emission outlet f and adapted to bear upon the flange b.

The rubber ring a restsat its inner side, namely that facing towards the magnetic system within the receiver, on the ledge 0 formed by the recess 2: in the casing a and is lightly pressed upon and supported on its opposite side, by a metal or other ring In (hereinafter called the bearing ring) having a number of spring fingers 7:, say three,

extending --radially inwards towards the central sound outletof the cover f and bearing against the inner side of the said cover. These fingers may lie in shallow grooves or recesses f formed in the cover. The said rubber ring a may, as shown, be of greater radial width'than the recess 0, so

that it is supported over 'onlyxa; portion of its radial width.

The bearing ring k may be arranged to bear lightly upon the rubber ring 0 embrac ing the edge portion of the d by slight pressure applied direct y to it in a downward or backward direction by means arranged directly between the bearing ring k and the cover. Figs. 2 and 2 show an arrangeme'nt of this kind wherein a bearing ring is is providedwith a-number of spring fingers k say three, that extend directly upward or outward therefrom and bear against the cover f so that the pressure exerted upon 7 or against the bearing ring is is applied directly downwards or backwards and applied lightly to the rubber ring 6 and the peripheral edge portion of the diaphragm (2 held thereby. The rear side of the cover 7 may be formed with a channel f to accommodate the be attached to the cover f, as by rivets 72 wherein the peripheral and act against the bearing ring is; or they may be fixed to the bearing ring 76 and bear against the cover f. I

The elastic bow shaped member k (Fig. 3) when fixed to the cover f, may bear di rectly on the rubber ring e, the bearing ring k belng then dispensed with. J

Figs. 4: and' 4* show an arrangement similar to Figs. 2 and 2 except that the bearing ring is wlth sprin fingers k is reversed in position, the ring eing accommodated in an annular recess f in the cover f and the spring fingers k bearing directly upon the rubber ring e.

According to a. further modified construe-- tion, the rear side of the cover f may be recessed directly above or in front of the bearing ring and a suitable number of rubber be. Is or pads, or coiled metal springs, or the like, be inserted and arrangedto bear directly upon or against the bearing rin and press the same lightly against the rub er ring e. The bearing ring in this case may be plain.

Figs. 5 and 5 show a further modification ortion of the diaphragm d is lightly'hel against a ring 6 of soft flexible material such as cloth, rubber or the like by light spring pressure, due for instance to that of a number of spring fingers is carried by a ring is housed in a groove f in the cover f. The spring fingers may be nular seat '0 i'n'the ca sing a plain as shown in Fig. 5" and bear directly against the diaphragm, as shown in Fig. 5,

or they ma each be provided with a small tip k of is t or'like soft material, as shown in Fig. 5", to bear directly against the diaphragm.

In some. cases, the outerpiri heral rtion of the diaphragm'may ghtly eld by ipring devices, such as the fingers shown in 1g. 5 or Fig. 5", directly against the ani the annular messes seating e, or cf of rubber, felt or like material' be dispensed with without departingirom the essential feature of the in vention. A greater advantage is however obtained by using a' rubber or like seating.

The cover may be secured to the casing of the telephonic receiver in any convenient .Way, as by screws m.

Telephonic receivers embodying the invention can be constructed in various ways without departing from the essential features of such invention. Thus, ity is to be understood that the expression cover herelet 7' may be formed in one piece with the casing a itself, and the diaphragm with rubber ring eand associated parts, if any, be introduced from the underside or rear side of the casing and be held in position by suitable retaining means, the 'electro-magnetic portion of the telephone receiver being afterwards fitted within the casing, or be carried by or upon a separate base to which the casing is secured. The retaining means may conveniently consist of cylindrical lining detachabl fixed within the casing a, and adapte to form therewith the recess a for the rubber ring a and diaphragm d, with associated parts, if any.

Although the arrangements herein disclosed for supporting or maintaining the diaphragm in position are described with particular reference to a form of telephonic receiver, such as described in the specification ofmy British LettersPatent No. 15369 of 1915, it will be readily understood the same means may be applied to the mounting of diaphragms of large dimensions whichmay not involve the necessity of employing anend plate or cover with central opening, but simply a ring of metal or other material forming an abutment, to retain the said diaphragm in position. In' this case the supporting members would be adapted to accommodate the means of diaphragmic mounting herein disclosed. Further,- the 'said means may be adapted to the diahragmic mounting of a telephonic receiver 1n which the diaphragm is not directly inences, for example, such as described in the ipecificationrof my British Letters Patent 25112 of1909. In fact, the method of hereinbefore dedia hragmic "scri d may 'epphfi .to the diaphragm I ment.

member in any form of telephonic instru- By employing constructions such as described, the diaphragm will be retained in position without any strain or stress being imparted thereto other than that imposed by the electro-magnet-ic system, and 'when influenced by variations in such system, an apperipheral portion of the diaphragm (1 against the stationary solid ring e, or annular seat 0 carried by the casing at the inner side of the diaphragm and serving as an inner abutment for the peripheral portion of the diaphragm; It is to be understood that the solid ring 6 of rubber, felt cloth or like sound deadening or damping material does not act as a springseat or sup port, but as a substantially rigid seat or support for the diaphragm d, like the hard seat a, but its use is preferred, as it forms a sound deadening means to prevent chatter of the diaphragm that might occur if the diaphragm be arranged to bear directly against the hard seat 0.

Having now particularly described and.

ascertained the nature of my said invention and in what manner the same is to be performed I declare that What I claim is 1. A telephonic receiver comprising a casing provided with arseat, an electro-magnetic diaphragminfluencing system within said casing, a diaphragm extending over said a diaphragm influencing system and supported by said seat, substantially rigid damping material arranged between said seat and the I peripheral portion of said diaphragm and adapted to exert 9.

against which the latter bears, an outer abut-.-

ment and sprin means arranged between the outer side 0% the peripheral portionof the-diaphragm and said outer abutment and yielding pressure against said diaphragm.

2. A telephonic receiver comprising a casing prpvided with a seat and an outer abutment, an electro magnetic diaphragm infiu encing system arranged within said casing,

- a diaphragm extending over saidwliaphragm influencing system and supported on said seat, a ring of sound damping material between said seat and the peripheral portion of said diaphragm and against which the latter bears, and sprin means having a plurality of yielding bearing points, said spring and supported means being arranged between and bearing against said outer abutment and the peripheral portion of said diaphragm and adapted to hold said-diaphragm in a yielding manner against said seat;-

3. A telephonic receiver comprising :1 casing provided with inner and outer substantially rigid abutments, an electro-magnetic dia hragm influencing siystem arranged wit in said casing, a iap ragm extendin over said diaphragm influencing system and having its outer periphery supportingly seated on said inner abutment, and means embod ing a plurality of sprin devices arranged between the said outer a utment and the peripheral portion of said diaphragm and adapted to hold said diaphragm in a yielding manner against said inner abuttment.

4. A telephonic receiver comprising a casing provided with an annular seat and at a distance .therefrom with an abutment, an

,electro-mag'netic diaphragm influencing system within said casing, a dia hragm extending over said diaphragm in uencings stein and supported at its periphery by sai seat, a bearing ring and a plurality of spring fingers arrangedbetween said abutment and the peripheral portion of said diaphragm and adapted to exert a yielding pressure on said diaphragm.

5. A telephonic receiver comprising a casing provided with an annular seat and at a distance therefrom with an abutment, an

electro-magnetic diaphragm influencing system within said casing, a diaphragm extending over said diaphragm influencing system,

and supported at itsperiphery b said seat and a bearing ring having a p urality of spring fingers integral therewith arranged between said abutment and the periphery of said diaphragm and adapted toexert a yielding pressure against the latter. w .6. A telephonic receiver comprising a casing provided with an annular seat and at a distance therefrom with an abutment, an

electro-magnetie diaphragm influencing system Within said casing, a dia hra extendingover said diaphragm i uencing stem and supported at its periphery by sai seat, a ring of sound dam ing material arranged between said seat an the peripheral portion of'said diaphragm and a bearing ring provided with aplurality of spring fingers arranged between said abutment and the peripheral portion of said diaphragm, said fingers being arranged to bear. at a plurality v of points against said diaphragm.

7. A telephonic receiver comprising a cas' ing provided with an annular seat and at a distance therefrom with an abutment, an

electro-magnetic diaphra m influencing system within said casing, a iaphra extend ing over said diaphragm influencing stem "at/ its periphery ysai seat,

Y a ring of soft damping material arranged between said seat and the peripheral portion of said diaphragm, a bearing ring provided with a plurality of spring fingers arranged between'said abutment and peripheral portion of said'diaphragm, said fingers being adapted to bear against the latter at a plurality of points, and sound damping means arranged between the tips of said fingers and the peripheral portion of said diaphragm.

8. A telephonic receiver comprising a casing provided with an annular seat and at a distance therefrom with an abutment, an electr c-magnetic diaphragm influencing system Within saideasing, a diaphragm extending over said diaphragm influencing systemand supported at its peripheryby said seat, a ring of soft sound damping material arranged between said seat and the peripheral portion of said diaphragm, a bearin 'ring provided with a plurality of spring ngers arranged between said abutment and the peripheral portion of said diaphragm, said fingers being arran ed to exert a yielding pressure against said diaphragm and a ring of soft sound damping material arrange between the diaphragm and the tips of said fingers.

Signed at London, England, this sixteenth day of May, 1924. I

EDWARD ALFRED GRAHAM. 

